From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ned Forrester Subject: Re: pxa2xx_spi with SFRM Date: Fri, 29 Aug 2008 23:07:05 -0400 Message-ID: <48B8B959.5010508@whoi.edu> References: <1218182539.489bfd8b24a3d@webmail.whoi.edu> <489C1B23.6040804@cam.ac.uk> <48A0C35D.5010606@gmail.com> <48A44F77.1020908@whoi.edu> <48A4ED85.1030803@gmail.com> <48A5D44D.6040106@whoi.edu> <20080815223307.02db86aa@vsauder-lx.localdomain> <48A9C0D0.5050304@whoi.edu> <48AB6C8F.4040408@whoi.edu> <20080821180826.491ac70b@vsauder-lx.localdomain> <48AF82B3.8040709@whoi.edu> <20080829151839.7a85e7d6@vsauder-lx.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org To: Vernon Sauder Return-path: In-Reply-To: <20080829151839.7a85e7d6-W37fpRALFaH6NKmgiXY+hA0JkcsJGQge@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: spi-devel-general-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Errors-To: spi-devel-general-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: linux-spi.vger.kernel.org With the one small change re: 8191, below, this looks good to go. For what it's worth, you can add below your sign-off: Reviewed-by: Ned Forrester It's time to add an appropriate [Patch] subject line to the patch, as outlined in the docs, and email it to David Brownell , with CC to the list. Thanks for pushing this; I know it takes time, and you are right that it needed to be done. Vernon Sauder wrote: > Ned, > > Sorry for the slow response. Real world/work intrudes sometimes. > > Here is another version of the patch along with responses to your > comments. > > Ned Forrester wrote: > >> Vernon Sauder wrote: >> >> Also note that the very recent patch that I submitted, tries to address >> a problem that you encountered with transfer lengths longer than 8192; >> in that case, I changed the behavior from "fail" to "do it in PIO mode >> with rate limited warning". Some day the driver could be rewritten to >> bust long transfers and do the pieces by DMA, but that is too ambitious >> for now. So you could add to the list of states that transfers longer >> than 8191 will be PIO. Have you tested that patch to see if it fixes >> any of your other problems? >> > > I did not try that patch yet. I added a comment to the doc about this. If you would try that it would be appreciated. I was waiting for your test to see if it fixed at least one of the MMC problems you were having (rejected long transfers) before I ask David to push the patch upstream. -------------------------------- > > Patch against Linus 2.6 tree after > 4c246edd2550304df5b766cc841584b2bb058843. It is compile tested only. > > --- > Subject: [PATCH] pxa2xx_spi: Fix chip_info defaults and documentation. > > Make the chip info structure data optional by providing reasonable > defaults. Improve corresponding documentation. > > DMA can determine appropriate dma_burst_size and thresholds > automatically so use DMA even if dma_burst_size is not specified. > > Signed-off-by: Vernon Sauder > --- > Documentation/spi/pxa2xx | 31 ++++++++++++++++++++----------- > drivers/spi/pxa2xx_spi.c | 43 ++++++++++++++++++++++++++----------------- > 2 files changed, 46 insertions(+), 28 deletions(-) > [snip] > The following logic is used to determine the type of I/O to be used on > a per "spi_transfer" basis: > > -if !enable_dma or dma_burst_size == 0 then > +if !enable_dma then > always use PIO transfers > > +if spi_message.len > 8192 then Oops. if > 8191 (or >=8192), a count of 8192 is not possible in the DMA controller. -- Ned Forrester nforrester-/d+BM93fTQY@public.gmane.org Oceanographic Systems Lab 508-289-2226 Applied Ocean Physics and Engineering Dept. Woods Hole Oceanographic Institution Woods Hole, MA 02543, USA http://www.whoi.edu/sbl/liteSite.do?litesiteid=7212 http://www.whoi.edu/hpb/Site.do?id=1532 http://www.whoi.edu/page.do?pid=10079 ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/